Hands On Open Source Development

1. Hands On Open Source Development Dr. Mark Pollack Sr. Staff Engineer: SpringSource

2. Introductions… • Who is this guy? • Who are you? • All about SpringSource and the Spring Framework • Project Goal: Build open source software • Using ‘modern’ development processes and tools • Why should you care?

3. Projects to develop • Portable “Blob” storage API • Data access library for the open source database CouchDB

4. Blob project • “Cloud” data storage is where many individuals and companies store data. • Your personal family pictures • Internal audit trail logs • Several public providers of this fully managed service • Amazon S3 • OpenStack • Microsoft Azure • Host your own service on your own infrastrucutre. • Eucalyptus • Riak • 10,000 ft project goals • API ease of use for common cases • API portability

5. Data Access library for CouchDB • What is CouchDB • Part of a new ‘wave’ of non-relational databases • Open source Apache project • Considered a ‘document’ database. Data is stored as a JSON document • HTTP/REST requests to interact with the database • “GET” – get a document • “PUT - put a new document • “DELETE” - delete a document • … • Query is done by creating ‘views’ on the document • Specifically using “Map/Reduce” framework in JavaScript • 10,000 ft. project goals • Provide full Java API for all HTTP requests • Simplify the storage of Java objects in the database • Simplify querying the database for common cases

6. Development Philosophy • Follow agile development principals • Adherence to core OO design principals • Decoupling, encapsulation, orthogonality • Unit/Integration tests • Rapid feedback on the impact of my own changes • Continuous integration • Rapid feedback on the impact of everyone else’s changes • Iterations/Sprints/Intervals… • “Stakeholder” feedback on the impact of changes

7. Traditional and Agile software development approaches • Traditional • Assumes change is avoidable • Manage change by sufficient pre-planning and design to avoid change • Big design up front • Agile • Assumes change is inevitable and unavoidable • Assumes impossible (or impractical) to plan-around change • Ties to manage change by ensuring the software remainds flexible enough or respond to change • Ensures that sufficient tooling, process and methods are in place to allow response to change within the context of an incredibly tight feedback loop

8. Key Practice : Version control • Manages the source code across the team • Mark known points in time for releases • We will also integrate source control with bug tracking • Version control is a requirement for Continuous Integration • Will use subversion for version control • Central repository model • You may have to handle merges when there are simultaneous changes to the same lines of code. • Will be hosted at SpringSource • Will use “Fisheye” to browse code on the web • See https://fisheye.springsource.org/browse

9. Key Practice: Continuous Integration • Automated way to enable us to rapidly respond to change while continuing to have working software. • Software that constantly checks out code and does the following • Compiles code • Run unit/integration tests • Run code metrics (optional) • Deploy (optional) And notifies you on failure… • We will use CI product “Bamboo” • Setup for you already. See http://build.springsource.org/ • Just need to check email for notification

10. Key Practice: Unit/Integration Testing • Developers write tests to ensure software behave as expected • May test an individual class in isolation (unit testing) or larger parts of the system collaborating together (integration testing) • Both are important • Regression harness • Feedback on code changes • Allows code to be changed/refactored quickly, easily, and safely in response to change in requirement, architecture, etc. • The quicker you find a bug, the cheaper it is to fix it • To follow this practice need to select a testing framework • We will use JUnit inside Eclipse

11. Key Practice: Bug, Issue, Project Tracking • Manage project goals for components, versions, timelines • “Issues” are entered into the system for new features • Estimates made when to complete stories • “Bugs” entered to report bugs • In practice used to drive much of the reporting and status of the project • We will use JIRA • See https://jira.springsource.org/secure/Dashboard.jspa

12. Product documentation • Many ways to provide this, SpringSource has generally settled on DocBook • XML schema defines book content. e.g. chapter, paragraph, etc. • XMLMind is a graphic semi WYSIWIG editor

13. General flow • Discuss/teach tools/process at each meeting • We will have a planning session at the beginning of each meeting • We will make goals, decide what’s required to achieve those goals, and the goals need to be measurable • We will also talk about how well we did, what we could have done better, and what to do for the next iteration- retrospective • We will also need to figure out the feasibility and estimate the time it will take to complete iterations • During iterations, if we have questions contact Mark via the mailing list. • 2 week iterations so iterations cycle=meeting cycle

14. Resources • “Big Picture” agile overview • Agile Samuari – some free chapters (on estimation) • Code Leader: Using People, Tools, and Processes to Build Successful Software • Agile Estimating and Planning – Mike Cohn • Agile Software Development, Principle, Patterns, and Practices – Bob Martin • http://www.agilefirestarter.com/ Free conference material (pdfs) • https://github.com/agilefire/November2010 (power poit) • Eclipse 3.6 or SpringSource Tool Suite 2.5.2 • http://eclipsetutorial.sourceforge.net/totalbeginnerlessons.html (videos!) • JUnit • www.junit.org (note: JUnit is already integrated into eclipse) • http://www.vogella.de/articles/JUnit/article.html • http://pragprog.com/titles/utj/pragmatic-unit-testing-in-java-with-junit (book)

15. Resources • Subversion • http://subversion.tigris.org/ • Tortoise SVN - http://tortoisesvn.tigris.org/ • http://subclipse.tigris.org/ eclipse add-in • http://svnbook.red-bean.com (free book) • Pragmatic Version Control using Subversion (book) • DocBook • http://www.docbook.org/ • http://www.xmlmind.com/xmleditor/ • JIRA • See videos/docs on http://www.atlassian.com/software/jira/ • Continuous Integration (“Bamboo”) • See videos on http://www.atlassian.com/software/bamboo/ • Continuous Delivery (book)

16. Resources • CouchDB • http://couchdb.apache.org/ • http://guide.couchdb.org/ (free book) • Amazon S3 • http://aws.amazon.com/s3/ • http://docs.amazonwebservices.com/AmazonS3/latest/gsg/ • http://www.sitepoint.com/books/cloud1/ book • Before, many out of date and difficult to read books on AWS/S3 out there…

17. Resources • Spring Framework • http://en.wikipedia.org/wiki/Spring_Framework • http://www.springsource.org/documentation • Spring in Action V3 (book) • Spring RestTemplate • http://blog.springsource.com/2009/03/27/rest-in-spring-3-resttemplate/ • Reference Manual • RESTful Web Services (book)

18. Fun for the weekend • Read the chapter on estimation in the Agile Samurai • http://media.pragprog.com/titles/jtrap/estimate.pdf • Take a look at CouchDB/Amazon S3 • With an eye to see which project you want to develop. If you are not familiar with Java/Eclipse/JUnit already start a bit with the following • Download latest Eclipse or SpringSource Tool Suite and get familiar with the environment • Follow the JUnit tutorial